Is it too late to amend 2018 tax info (1099sa, 8889) on HSA to address 2019 excess contributions made to cover 2018 medical expenses?

I had large, unexpected medical expenses Dec 2018 into 2019 (2 surgeries). I had not met my contribution limit for 2018 but have now exceeded the 2019 limit with personal contributions to cover my medical bills. Can I adjust my 2018 filing to make a Jan 2019 contribution (made to cover Dec 2018 medical bill) part of my 2018 contributions? Do I need to contact the bank to adjust my 1099sa/8889?